<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <script>
        var a1=['1','2','3'];
        var a2=['4','5','6'];
       /* console.log(a1.concat(a2));
        console.log(a1);
        console.log(a1.join('-'));
        console.log(a2.reverse());*/

       /* console.log(a1.slice(1));
        console.log(a2.pop());
        console.log(a2.shift());*/

       /* a1.push(4)
        console.log(a1);//返回值数字4
        a2.unshift(3)
        console.log(a2);//返回值数字4*/

       a2.splice(1,1,'a','b');
        console.log(a2);
    </script>
</body>
</html>